Formed between the years 1905 and 1907, the Salton Sea came into being when poorly constructed irrigation controls along the Colorado River that were south of Yuma, Arizona were destroyed. The water slowly began filling up the Salton Basin and indunated many communities, farms and the main line of the Southern Pacific Railroad.
The filling of the Salton Basin was halted when a protective levees were built by boxcars dumping boulders into the breach from Southern Pacific tracks. By then, this inland lake was about 40 miles long and 13 miles wide, covering an area of about 400 square miles.
The Salton Sea is currently 35 miles by 15 miles and can be as long as 40 miles by almost 20 miles in particularly wet years. It has an average depth of 29.9 feet and, at its deepest, is 51 feet. It contains 7.3 million acre feet of water and evaporates 1.3 million acre feet each year. There is a five-mile-long trench on the south end of the Sea that is 51 feet deep. The Sea is currently 228 feet below sea level. Interestingly, the bed of the Salton Sea is only five feet higher than the lowest spot in Death Valley.
Presently, the fishery in the Salton Sea is thriving. Salinity is slightly more than the Pacific Ocean. The current salt level of the Sea is in the area of 41 to 43 TH PPM. The Pacific Ocean is about 34.9 TH PPM.. If the concentrated salt level of the Sea increases greater than 44 TH PPM., it is expected that all the fish, except the Tilapia, will cease to reproduce. Tilapia can survive up to 60 TH PPM.
Sources
http://www.desertusa.com/salton/salton.html